Ovfork.S revision 39140
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $Id: Ovfork.S,v 1.8 1998/09/12 22:03:08 dt Exp $ 37 */ 38 39#if defined(SYSLIBC_RCS) && !defined(lint) 40 .text 41 .asciz "$Id: Ovfork.S,v 1.8 1998/09/12 22:03:08 dt Exp $" 42#endif /* SYSLIBC_RCS and not lint */ 43 44#include "DEFS.h" 45#include "SYS.h" 46 47/* 48 * pid = vfork(); 49 * 50 * %edx == 0 in parent process, %edx == 1 in child process. 51 * %eax == pid of child in parent, %eax == pid of parent in child. 52 * 53 */ 54 55#ifdef _THREAD_SAFE 56ENTRY(_thread_sys_vfork) 57#else 58ENTRY(vfork) 59#endif 60 popl %ecx /* my rta into ecx */ 61 lea SYS_vfork,%eax 62 KERNCALL 63 jb verror 64vforkok: 65 cmpl $0,%edx /* child process? */ 66 jne child /* yes */ 67 jmp parent 68 69 .globl CNAME(__error) 70 .type CNAME(__error),@function 71verror: 72 pushl %eax 73#ifdef PIC 74 call PIC_PLT(CNAME(__error)) 75#else 76 call CNAME(__error) 77#endif 78 popl %edx 79 movl %edx,(%eax) 80 movl $-1,%eax 81 movl $-1,%edx 82 jmp %ecx 83child: 84 movl $0,%eax 85parent: 86 jmp %ecx 87